No, you don't have to be big and strong, but you are a guy. Gender is a word made-up in the fifties to cause a split between what you are and what you think you are in the public's mind. All the transgender thing does is enforce stereotypes. "Your a man but you like pink? You are obviously a girl" "your a girl but don't like dolls? Must be a boy" people can like whatever they do, that doesn't change their identity. Sex/gender is like skin/eye color, you are what you are, no reason to feel bad about it. It's unchangeable.
